There are several adaptors at Ebay or Amazon for around 10-20 Euros.
I'm using a sintech adaptor to use a normal M.2-NVMe SSD (Samsung Evo 970 Plus) in my 2019 iMac. No problems at all.
For Samsung SSDs, be sure, you have the very latest firmware on your SSD installed (i'd used a Windows laptop and an external enclosure for updating the firmware) and you will need at least macOS High Sierra to support NVMe-SSDs.
For frequent firmware updates, i have a bootstick with Bootcamp/Windows, because absolutely no manufacturer supports firmware upgrades via macOS and only Crucial(Micron) is providing a Linux based upgrade volume.